The disclosure relates generally to controlling the optical axis of a birefringent material, and more specifically to generating composite optical coatings with linearly polarized patterns on a curved optical surface.
In head-mounted displays (HMDs), folded optical systems may be used to significantly reduce the thickness and weight of the optical system inside the HMDs by means of a folded optical path. Such optical systems may include a quarter wave-plate compatible with a broad band of optical wavelength (e.g. 450 nm to 650 nm) for converting a linearly polarized light to a circularly polarized light. Conventional approaches such as Quarter-Half-Quarter design are currently used to form a quarter-wave plate on a flat optical surface. However, for manufacturing pancake lenses with a highly curved optical surface (e.g. radius of curvature of ˜42 mm), methods currently used to form a quarter-wave plate on a curved optical surface are mostly based on lamination on curved optical surfaces. Among several other limitations, lamination based approaches to form a quarter-wave plate on a curved optical surface often induce artifacts (e.g. wrinkles and bubbles) during heating and stretching that result in an increased scattering of light, and increased difficulty to control a spatial orientation of the optical axis across the quarter-wave plate created on a curved optical surface.